How to get multiple counts with one SQL query?

Question

I am wondering how to write this query.

I know this actual syntax is bogus, but it will help you understand what I am wanting. I need it in this format, because it is part of a much bigger query.

SELECT distributor_id,  COUNT(*) AS TOTAL,  COUNT(*) WHERE level = 'exec',  COUNT(*) WHERE level = 'personal' 

I need this all returned in one query.

Also, it need to be in one row, so the following won't work:

'SELECT distributor_id, COUNT(*) GROUP BY distributor_id' 

Answer 1

You can use a CASE statement with an aggregate function. This is basically the same thing as a PIVOT function in some RDBMS:

SELECT distributor_id,     count(*) AS total,     sum(case when level = 'exec' then 1 else 0 end) AS ExecCount,     sum(case when level = 'personal' then 1 else 0 end) AS PersonalCount FROM yourtable GROUP BY distributor_id 

Answer 2

One way which works for sure

SELECT a.distributor_id,     (SELECT COUNT(*) FROM myTable WHERE level='personal' and distributor_id = a.distributor_id) as PersonalCount,     (SELECT COUNT(*) FROM myTable WHERE level='exec' and distributor_id = a.distributor_id) as ExecCount,     (SELECT COUNT(*) FROM myTable WHERE distributor_id = a.distributor_id) as TotalCount FROM (SELECT DISTINCT distributor_id FROM myTable) a ; 

EDIT:
See @KevinBalmforth's break down of performance for why you likely don't want to use this method and instead should opt for @Taryn♦'s answer. I'm leaving this so people can understand their options.